#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<stdint.h>
using namespace std;
class a
{
public:
	
	int64_t c_fun(int64_t n)
	{
		return n - 12;
	}
};
int main()
{
	int64_t n;
	cin >> n;
	cout << a().c_fun(n) << endl;
	return 0;
}